As a basic configuration of a power module configuring a power conversion device, a power circuit substrate, and a cooling fin, there is a configuration disclosed in, for example, JP-A-2002-325467 (Patent Document 1). The power conversion device disclosed in Patent Document 1 incorporates an inverter configured of a semiconductor element, and has a power module electrically isolated from the inverter and a cooling fin configured of an electrically conductive material to which the power module is attached, wherein sealing of the module with a non-electrically conductive, thermally conductive fluid resin is realized by a wall enclosing the module being provided on a module attachment face of the cooling fin.